Teachers unions celebrated the California Supreme Court's decision Monday to refuse to hear a major case involving whether the state's tenure laws hurt poor and minority students.

The labor groups have shied away from acknowledging what the case, called Vegara v. California, was about, however, refusing to even use the word "tenure" in their official statements. The refusal illustrates the extent to which even the unions fear the tenure debate may be hurting their image with the public.

In 2014, California Superior Court Judge Rolf Treu ruled in favor of nine students who sued the state, saying the tenure policies undermined education by making it almost impossible for bad teachers to be fired. In April, a state appeals court overturned the ruling, and on Monday the state supreme court affirmed the appeals court's decision.

Had Treu's decision been upheld it would have been a severe blow to the unions by eliminating the main source of job security for teachers. School administrators would have had a free hand to terminate contracts if they decided the teachers were not were not giving a good education to their students.

Under current state tenure law, educators become eligible for tenure after less than two years on the job. Firing a tenured teacher, even one who performs extremely poorly, can take as long as a decade and cost the state as much as $450,000. In practice, dismissals are rare.

Rather than address the issue that was at the center of the case, the unions presented Vergara as a simple attack on teachers' rights. "This is a good day for students and educators as the Supreme Court's decision brings an end to the case brought by wealthy anti-public education millionaires who spent millions of dollars to bypass voters, parents and the legislature in an attempt to impose their harmful education agenda on local schools," said California Teachers Association President Eric C. Heins.

Joshua Pechthalt, president of the California Federation of Teachers, said the decision would allow the union to focus on obtaining more state funding instead. "We can now turn closer attention to solving the actual problems we confront in our schools, such as securing adequate funding through Prop. 55, reducing class sizes, promoting and strengthening peer assistance and review, and reinforcing collaborative district practices with a proven record of success," Pechthalt said.

National teachers unions made the same argument. Randi Weingarten, president of the 1.6 million member American Federation of Teachers, said: "I hope this decision closes the book on the flawed and divisive argument that links educators' workplace protections with student disadvantage." AFT is the parent union of the California Federation of Teachers.

None of the unions' statements mentioned the word "tenure."

Education reform advocates lamented the decision. "Tenure discourages great teachers by protecting those who might not be able to keep their job if they had to prove their success. This decision is bad for aspiring teachers and bad for kids," said Jeanne Allen, founder and CEO of the Center for Education Reform.

Tenure has been a touchy issue for teachers unions. Support for reform is strong even in liberal states such as California. A 2014 survey by the University of Southern California found that 61 percent opposed the state's tenure rules, including 53 percent of Democrats. Treu's ruling was even cheered by former Rep. George Miller, D-Calif., long one of organized labor's staunchest supporters in Congress.

Treu's initial ruling found that there was "no dispute that there are a significant number of grossly ineffective teachers currently active in California classrooms." He ordered the state education code statutes relating to teacher tenure be stayed pending appeals court review. The appeals court subsequently reversed him. On Monday the state Supreme Court said Treu's ruling was improper because it was not clear the tenure laws themselves were directly responsible for ineffective teachers.

"Plaintiffs failed to establish that the challenged statutes ... inevitably cause a certain group of students to receive an education inferior to the education received by other students," the court said.